PTL, Push To Listen.
Just push the button and speech "outside" the muff cup can be heard "inside" clearly and safely (up to 87 dB).
After 30 seconds the muff automatically returns to its full protection with an NRR of up to 26 dB*.

No more lifting the muff to communicate with coworkers
Electronic hearing without the usual electronic price premium
Padded, wide headband with four-point steel suspension
Battery compartment designed for easy access

* Note that the NRR may overestimate the hearing protection provided during typical use.
3M recommends reducing the advertised NRR by 50% for estimating the actual amount of noise reduction provided.